Off-air recordings of various shortwave pirate radio broadcasts as heard from my home in Texas since 2007. Mostly North American free/pirate shortwave radio broadcasts, I do occasionally snag a European station when conditions are favorable.
Most were recorded using a direct line-out connection from a Palstar R30C receiver to a computer, using a shielded audio patch cord fitted with simple ferrite chokes to control the hum/buzzing noise that sometimes occurs with direct connections between a radio's line out and computer audio input.
I'll typically use Audiograbber or an ancient copy of Cool Edit Pro to record and save in 32 kbps/22 kHz or better mp3. Other DXers report satisfaction with Audacity, mp3DirectCut and other free, shareware or affordable audio recording/editing programs. Since suburban RFI is fairly high here in evenings, occasionally I'll apply hiss/noise reduction to clarify some recordings.
Until around late 2009 I mostly used a 30' random wire antenna made from thin magnet wire, strung up a tree near my apartment window. Due to heavy local suburban RFI I switched in 2010 to a homebrewed untuned passive magnetic loop mounted indoors near a window. In late 2011 I modified the loop to use a smaller pickup loop and an amplifier with tuner, which seemed to improve signal to noise by further nulling out RFI from nearby flickering streetlights. In 2015 I switched to a stealthy outdoor loop made of magnet wire strung along a nearby wooden fence to form a loop measuring roughly 6'-8' along each of four sides, fed via a TV balun (not ideal for HF, but functional) and TV coaxial cable to my receiver. It's cheap and easily replaceable if discovered and torn down. And it gets the best reception yet of any homebrewed cheap antenna I've tried here.
While far from ideal, my reception often equals and occasionally surpasses reception of the same pirate stations when compared against Global Tuners remote stations scattered around the world. With the currently poor propagation and solar cycle conditions, a low noise antenna, persistence and luck help. With a low-noise loop I can leave the receiver on continuously and not go nuts from static.
For a sampling of better quality and more diverse off-air recordings, check the collections by Sealord and Ragnar Daneskjold.